Modern premium windows are designed to be tilted for cleaning. The window is usually configured to fix two points on the window sash to act as a hinge for tilting. Specifically, such windows have a frame which includes track liners, such as a sill liner and a head liner, and means, such as trucks, for enabling the sash to easily slide within the frame.
One of the problems of tilting windows is that once the window tilts out of the plane of the window frame, if the hinge points undesirably slide in the frame, the window may fall out on the homeowner. This problem has been solved by providing a brake for the hinge points, activated by the tilting action of the window. Prior art brakes for these windows are not as foolproof as desired. Typically, the brake involves a cam or other member which is expanded or pushed against the side or bottom of the track liner. This has been known to fail, giving rise to the possibility of a falling window.
Another problem with prior art brakes to be installed in track liners of windows is that in order for the brakes to provide sufficient stopping action when they are engaged, they are oftentimes configured to somewhat inhibit the easy slidability of the sash within the frame when the brakes are not engaged. Preferably, the brakes provide an excellent grip or braking action when engaged, and yet provide no inhibition to the slidability of the frame within the sash while the brake is not engaged.
Another desirable attribute of braking systems for tilting windows is that the system be designed so that the window cannot be tilted until the brake is completely engaged. Many prior art brake systems are designed so that the brake system is actuated by the movement of a lever or by the actual tilting action of the window itself. In such systems, the braking action begins immediately, but is not fully engaged or completed until the full tilting action of the window is completed, or until the full movement of the lever is completed. In such systems, the window can be tilted before the brake is completely engaged, thereby opening up the possibility of a window falling out of the frame.
There is a need for an improved brake system which provides for easy slidability when the brake is not engaged, provides a sure braking action which will not enable any sliding of the window when the brake is engaged, and provides a positive foolproof system which assures that the brake system is completely activated before the sash can be tilted out of the plane of the frame.